An automobile has an engine and a battery, wherein the battery is charged with power of the engine. A known technique of charge control for charging the battery suppresses the battery from being charged during normal running to save the amount of fuel consumption, while allowing the battery to be charged by regenerative power generation during deceleration running.
Idle reduction control is also known as the technology to save the amount of fuel consumption. Patent Literature 1 given below discloses an automobile having both the function of charge control and the function of idle reduction control, in order to meet the requirement for improvement of fuel consumption. A known configuration of a charge control device increases the generated voltage of an alternator with an increase in consumed current of auxiliary machinery (for example, Patent Literature 4).